Optical coupler for an endoscope

ABSTRACT

Companion and accessory devices for endoscopes are provided that include an optical coupler. The optical coupler comprises an attachment section comprising one or more elastic material(s) and dimensioned to be removably attached to a distal end of the endoscope and a visualization section in contact with the attachment section and at least partially surrounds a distal surface of the endoscope. The visualization section is configured to allow transmission of an optical image therethrough. The coupler further includes one or more supporting elements extending away from the attachment section or the visualization section for maintaining the endoscope substantially within the center of a body lumen as the endoscope advances therethrough.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/881,663, filed May 22, 2020, which is acontinuation of U.S. patent application Ser. No. 16/512,676, filed Jul.16, 2019, which is a divisional application of U.S. patent applicationSer. No. 14/538,313, filed Nov. 11, 2014, which is a divisionalapplication of U.S. patent application Ser. No. 13/398,277 filed Feb.16, 2012, which claims priority to U.S. Provisional Patent ApplicationNo. 61/443,546 filed Feb. 16, 2011, which are all hereby incorporated byreference as if set forth in their entirety for all purposes.

BACKGROUND

The demand for minimally invasive surgery continues to grow. The abilityto convert open surgeries to minimally invasive procedures has been madepossible with video endoscopy, but is limited when blood or other fluidsare in the field of view. Other technologies (fluoroscopy, 3-D echo,MRI, etc.) currently are used to overcome the challenge of performingsurgery in intravascular spaces, but each technology presentslimitations.

Fluoroscopy has a two dimensional view and is used for diagnosticprocedures or placement, and/or deployment of medical devices.Procedures are lengthy creating increased exposure to radiation for bothpatients and clinicians, increased expense, and also may increasemorbidity due to extended anesthesia duration. Most importantly, imagesare inferior to direct vision, the gold standard in surgery. Ultrasoundthree dimensional imaging systems have known problems as well. Imagesare created by transforming ultrasound waves to images. Images oftencontain shadowing or ghosting when instruments or devices are placedwithin the viewing field. MRI surgical procedures are very limited,costly and complex. Simple procedures take hours.

What is needed therefore is a device that allows diagnostic and surgicalprocedures to be performed in areas of the body where visibility isnormally or has been obstructed by blood, stomach content, bowelcontent, or other opaque fluids and/or solid particulate matter.

SUMMARY

The foregoing needs are met by an optical coupler comprising a clear gelin a semi-solid state that attaches to the distal end (objective lens)of a conventional or modified video endoscope for performing diagnosticprocedures and/or minimally invasive surgical operations. The opticalcoupler is biocompatible and for single use. It can be attached to rigidor flexible endoscopes (for example, gastroscopes thorascopes,laparoscopes, colonoscopes, Natural Orifice Transluminal EndoscopicSurgery (NOTES) endoscopes, esophagoscopes, nasolarynoscopes,arthroscopic scopes and ophthalmoscopes used in laparoscopic,gastrointestinal, thorascopic, colonoscopy and other endoscopicprocedures). The optical coupler is an important advancement inminimally invasive surgeries and as a tool utilized in diagnosis andtreatment of disease.

The optical coupler is used for visualization in opaque fluids orsemisolids, and comprises a clear, soft, flexible gel coupled to theouter distal portion of any optical imaging device, such as an endoscopeor a camera lens. When pressed in contact with the surface of an area tobe viewed, the coupler creates an offset that allows clear visualizationby mechanically displacing the opaque liquid, semisolids, or particulatematter. This displacement allows the optically clear coupler to comeinto contact with a surface of interest, thus producing an unobstructedview to the observer.

In a non-limiting medical embodiment, the coupler solves a long-standingmedical challenge: keeping the tissue undergoing diagnostic or surgicalrepair free of blood, bile, and/or other opaque fluids that wouldobstruct the clinician's view. Because the coupler comprises a clearsoft elastic gel, standard medical instruments can be maneuvered withinthe area of the offset, giving the clinician seamless access and a clearview of tissue in situ. The coupler provides for reduced surgicalprocedure time resulting in less invasive effects and quicker patientrecovery, and potentially higher volume of scheduled procedures. Thecoupler is intuitive to use and would not require any learning curve forthe clinician.

In a non-limiting industrial embodiment, the coupler can be attached toa borescope, pipe inspection or other imaging equipment to evaluate orrepair surfaces obstructed by opaque fluids or solutions, semisolids, orparticulate matter, such as oil, sewage or silt.

In one aspect, an optical coupler for mounting at a distal end of anoptical imaging device for visualizing a surface area covered with anopaque fluid and/or particulate matter. The coupler includes avisualization section at one end of the coupler and an attachmentsection connected to and extending away from the visualization section.The attachment section is dimensioned to be mounted at the distal end ofthe optical imaging device. The visualization section includes aproximal surface for engaging the distal end of the optical imagingdevice. The visualization section includes an outer surface spaced apartfrom the proximal surface. The outer surface extends continuously from afirst outer side boundary across to a second opposite outer sideboundary of the visualization section. The coupler further includes anattachment section connected to and extending away from thevisualization section. The attachment section is dimensioned to bemounted at the distal end of the optical imaging system.

In certain embodiments, the optical coupler may include one or moresupporting elements extending laterally away from the optical coupler tofacilitate passage of the coupler through a lumen, such as lumen withina patient. The supporting elements may extend from the attachmentsection, the visualization section or both. The supporting elements maybe dimensioned to contact an internal surface of an object beingvisualized (e.g., a lumen within a patient's body) when the device ispositioned within the object. The supporting elements may further bedimensioned to maintain the position of the optical couplersubstantially in the center of the object, such as a body lumen. In apreferred embodiment, the supporting elements extend at an angletransverse to the longitudinal axis of the coupler.

The visualization section may include a hollow instrument channelextending from the proximal surface toward or through the outer surface.The visualization section may include a self-sealing element within theinstrument channel to enable the visualization section to be pierced byan instrument and reseal after withdrawal of the instrument from thevisualization section. In certain embodiments, the instrument channelexits through the outer surface of the optical coupler such that aninstrument passing through the channel remains visible in a field ofview of the optical imaging system. In one such embodiment, theinstrument channel is adjacent to an outer surface of the opticalimaging device. In another embodiment, the instrument channel is movablycoupled to one portion of the optical coupler.

In certain embodiments, the optical coupling system further includes adisposable outer sheath sized and dimensioned to fit around the cannulaof the optical imaging system. The sheath may be coupled to, or integralwith, the optical coupler. The outer sheath may further include one ormore hollows channels therein for passage of instruments, insufflationor the like. In this embodiment, the entire sheath and optical couplermay be configured as a single-use disposable system to facilitatecleaning of the reusable optical imaging system.

The visualization section can be formed from an elastic material capableof transmitting an optical image of the surface area. In one form, thematerial comprises a silicone gel or a silicone elastomer.

In another aspect, the optical coupler may include an adjustmentmechanism for adjusting the field of view of the lens of the opticalimaging device. The adjustment mechanism may reduce reflections in thefield of view of the lens and/or concentrate light within the field ofview of the lens. In certain embodiments, the adjustment mechanismcomprises an adjustment lens within the visualization section. In otherembodiments, the adjustment mechanism comprises one or more lightreflecting surfaces, such as mirrors or the like, within thevisualization section. In yet another embodiment, the adjustmentmechanism includes a second material within the visualization systemthat redirects and/or capture the light from the lens.

In another aspect, a device for visualizing a surface area covered withan opaque fluid and/or particulate matter. The device includes a sheathhaving a first lumen and a second lumen, a light guide positioned in thefirst lumen for transmitting light toward the surface area, an imagecarrying fiber positioned in the second lumen, an object lens positionedat a distal end of the image carrying fiber and optically connected tothe image carrying fiber wherein the lens receives light that has beenreflected from the surface area, and an optical coupler mounted at adistal end of the sheath. The coupler includes a visualization sectionat one end of the coupler. The visualization section includes a proximalsurface for engaging the distal end of the optical imaging device, andthe visualization section includes an outer surface spaced apart fromthe proximal surface wherein the outer surface extends continuously froma first outer side boundary across to a second opposite outer sideboundary of the visualization section.

The visualization section includes a hollow instrument channel extendingfrom the proximal surface toward the outer surface. The visualizationsection can comprise an elastic material capable of transmitting anoptical image of the surface area. The coupler includes an attachmentsection connected to and extending away from the visualization sectionwherein the attachment section is dimensioned to be mounted at thedistal end of the optical imaging device.

In yet another aspect, a method is described for visualizing a walldefining a body cavity with an endoscope wherein the wall is covered orobstructed with an opaque fluid and/or particulate matter. The methoduses an endoscope comprising a sheath having a first lumen and a secondlumen, a light guide positioned in the first lumen, an image carryingfiber positioned in the second lumen, and an object lens positioned at adistal end of the image carrying fiber wherein the lens is opticallyconnected to the image carrying fiber. An optical coupler is mounted ona distal end of the sheath. The coupler includes a visualization sectionat one end of the coupler. The visualization section includes a proximaltransverse surface engaging the distal end of the sheath. Thevisualization section includes an outer surface spaced apart from theproximal surface wherein the outer surface extends continuously from afirst outer side boundary across to a second opposite outer sideboundary of the visualization section, and the visualization sectioncomprises an elastic material capable of transmitting an image of thesurface area. The endoscope is inserted into the body cavity, and theoptical coupler is positioned in contact with a region of the wall ofthe body cavity thereby displacing opaque fluid and/or particulatematter adjacent the region. Light is transmitted through the light guideand optical coupler onto the region, and light that has been reflectedfrom the region is received at the lens and an optical image istransmitted from the lens to the image carrying fiber.

In still another aspect, a method is described for visualizing a walldefining a body cavity with an endoscope where the wall is covered withan opaque fluid and/or particulate matter. The method includes the stepsof: (a) providing an endoscope comprising (i) a sheath having a firstlumen, a second lumen, a third lumen and a fourth lumen, (ii) a lightguide positioned in the first lumen, (iii) an image carrying fiberpositioned in the second lumen, and (iv) an object lens positioned at adistal end of the image carrying fiber wherein the lens is opticallyconnected to the image carrying fiber; (b) inserting the endoscope intothe body cavity; (c) feeding a first precursor through the third lumenand feeding a second precursor through the fourth lumen such that thefirst precursor and the second precursor react to form an opticalcoupler on a distal end of the sheath. The first precursor can be anoptical fluid and the second precursor can be a cross linking agent.

The coupler includes a visualization section at one end of the coupler.The visualization section includes a proximal transverse surfaceengaging the distal end of the sheath, and the visualization sectionincludes an outer surface spaced apart from the proximal surface. Theouter surface extends continuously from a first outer side boundaryacross to a second opposite outer side boundary of the visualizationsection, and the visualization section comprises an elastic materialcapable of transmitting an image of the surface area. The opticalcoupler is positioned in contact with a region of the wall of the bodycavity thereby displacing opaque fluid and/or particulate matteradjacent the region. Light is transmitted through the light guide andoptical coupler onto the region, and light that has been reflected fromthe region is received at the lens and an optical image is transmittedfrom the lens to the image carrying fiber.

In still another aspect, a method is described for visualizing a surfaceof a structure with a camera, the surface being covered with an opaquefluid and/or particulate matter. The method includes (a) providing acamera having a lens and a source of light and (b) mounting an opticalcoupler on the camera by engaging the optical coupler on an outersurface of the camera, the coupler including a visualization section atone end of the coupler, the outer surface extending continuously from afirst outer side boundary across to a second opposite outer sideboundary of the visualization section, and the visualization sectioncomprising an elastic material capable of transmitting an image of thesurface area. The method also includes (c) placing the camera and theoptical coupler near the surface of the structure, (d) positioning theoptical coupler in contact with a region of the surface of the structurethereby displacing opaque fluid and/or particulate matter adjacent theregion, (e) transmitting light from the light source through the opticalcoupler onto the region, and (f) receiving at the lens, light that hasbeen reflected from the region and capturing an optical image on thecamera.

In yet another aspect, a method is described for visualizing a surfaceof a structure with a borescope, the surface being covered with anopaque fluid and/or particulate matter. The method includes (a)providing a borescope comprising (i) a sheath having a first lumen, asecond lumen a third lumen and a fourth lumen, (ii) a light guidepositioned in the first lumen, (iii) an image carrying fiber positionedin the second lumen, and (iv) an object lens positioned at a distal endof the image carrying fiber, the lens being optically connected to theimage carrying fiber; (b) placing the borescope near the surface; and(c) feeding a first precursor through the third lumen and feeding asecond precursor through the fourth lumen such that the first precursorand the second precursor react to form an optical coupler on a distalend of the sheath, the coupler including a visualization section at oneend of the coupler, the visualization section including a proximaltransverse surface engaging the distal end of the sheath, thevisualization section including an outer surface spaced apart from theproximal surface, the outer surface extending continuously from a firstouter side boundary across to a second opposite outer side boundary ofthe visualization section, and the visualization section comprising anelastic material capable of transmitting an image of the surface area.The method also includes (d) positioning the optical coupler in contactwith a region of the surface of the structure thereby displacing opaquefluid and/or particulate matter adjacent the region; (e) transmittinglight through the light guide and optical coupler onto the region; and(f) receiving at the lens, light that has been reflected from the regionand transmitting an optical image from the lens to the image carryingfiber.

In yet another aspect, a hand-held device includes a handle providing auser a portion to grip and a frame connected to the handle. The framehas a cavity. A transparent section is held within the cavity, thetransparent section can be punctured.

These and other features, aspects, and advantages of the presentdescription will become better understood upon consideration of thefollowing detailed description, drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a first embodiment of an optical coupler.

FIG. 2 is a cross-sectional view of the optical coupler of FIG. 1 takenalong line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view of the optical coupler of FIGS. 1 and 2taken along line 3-3 of FIG. 2, the optical coupler being attached to anendoscope.

FIG. 4 is a cross-sectional view similar to FIG. 3 of a secondembodiment of an optical coupler, the optical coupler being attached toan endoscope.

FIG. 5 is a cross-sectional view similar to FIG. 4 of the secondembodiment of the optical coupler engaging an inner wall of a bodycavity.

FIG. 6 is a cross-sectional view similar to FIG. 4 of the secondembodiment of the optical coupler engaging an inner wall of a bodycavity wherein a medical instrument has been advanced through aninstrument lumen of the endoscope, an instrument channel of the opticalcoupler, a solid body of the optical coupler, and against the inner wallof the body cavity.

FIG. 7 is a cross-sectional view similar to FIG. 3 of a third embodimentof an optical coupler, the optical coupler being attached to anendoscope.

FIG. 8 is a side view of another embodiment of an optical couplersimilar to the coupler in FIGS. 1 and 2, but with the instrument channelextended through the outer surface.

FIG. 9 is a cross-sectional view of the optical coupler of FIG. 8 takenalong line 9-9 of FIG. 8.

FIG. 10 is a side view of another embodiment of an optical coupler wherethere is not an instrument channel in the coupler, and an electrode andwire are molded into the coupler.

FIG. 11 is a cross-sectional view of the optical coupler of FIG. 10taken along line 11-11 of FIG. 10.

FIG. 12a is a cross-sectional view of another embodiment of an opticalcoupler attached to an endoscope with a biopsy forceps placed throughthe endoscope and into the optical coupler, the jaws of the biopsyforceps being opened.

FIG. 12b is a cross-sectional view of the embodiment in FIG. 12a , withthe jaws of the biopsy forceps closed to take a biopsy sample.

FIG. 12c is a cross-sectional view of the embodiment in FIGS. 12a and12b , with the biopsy forceps being withdrawn after having taken thebiopsy sample.

FIG. 12d is a detailed view of the embodiment shown in FIG. 12 a.

FIG. 13a is a side view of another embodiment of an optical couplerwhere the outer surface of the optical coupler is angled.

FIG. 13b is a side view of the embodiment in FIG. 13a , where theoptical coupler is inspecting a weld.

FIG. 14a is a perspective view of an optical coupler similar to theoptical coupler shown in FIG. 12a -FIG. 12c , but the optical coupler isattached to a camera.

FIG. 14b is a front view of the optical coupler and camera in FIG. 14a ,with the optical coupler and camera placed in a pipe filled with aliquid.

FIG. 15a is perspective view of an optical coupler and camera similar tothe embodiment shown in FIGS. 14a and 14b , with a semi-rigid tubeplaced parallel to the camera and through the optical coupler.

FIG. 15b is a front plan view of the optical coupler and camera in FIG.15a , with the optical coupler and camera examining a defect in a pipefilled with liquid.

FIG. 16 is a cross-sectional view of another embodiment of an opticalcoupler attached to an endoscope that has an auxiliary fluid channel.

FIG. 17a is a cross-sectional view of a coupler having a concave outersurface that is attached to an endoscope approaching tissue covered inblood.

FIG. 17b is a cross-sectional view of the coupler and endoscope fromFIG. 17a , with the coupler pressed against a wall.

FIG. 17c is the cross-sectional view of the coupler and endoscope fromFIG. 17b , with fluid from the instrument channel flushing the trappedopaque liquid between the outer surface of the coupler and the wall.

FIG. 18a is a side plan view of a coupler attached to an endoscope withthe use of a cap.

FIG. 18b is an exploded view of the coupler of FIG. 18 a.

FIG. 19 is a coupler attached to a rigid endoscope having a 0° endsurface, with the coupler having an angled instrument channel.

FIG. 20 is a coupler attached to a rigid endoscope having a 30° endsurface, with the coupler having a straight instrument channel.

FIG. 21 is another embodiment of a coupler attached to an endoscope, thecoupler being made of multiple materials.

FIG. 22a is a perspective view of a coupler used in a handheld device.

FIG. 22b is a cross-sectional view of the coupler of FIG. 22a , with astapler passing through the coupler to treat a laceration.

FIG. 23a is a front plan view of a mold that can be used to make acoupler.

FIG. 23b is an exploded view of the mold of FIG. 23 a.

Like reference numerals will be used to refer to like parts from Figureto Figure in the following description of the drawings.

DETAILED DESCRIPTION

An optical coupler is provided for improved optical imaging of surfacescovered with opaque fluids, semisolid materials or particulate matter.In one form, the optical coupler is a clear gel attached to the outerdistal portion of any optical imaging or image capturing device, such asan endoscope or camera lens. When pressed in contact with the surface ofan area to be viewed, the gel creates an offset that allows clearvisualization by mechanically displacing the opaque liquid or softsemisolids.

An attachment section of the optical coupler can be mounted on thedistal portion of the insertion part of the endoscope. A visualizationsection of the optical coupler comprises a soft, elastic, flexible,optically clear gel, and covers the distal end of the endoscope. Thevisualization section of the optical coupler may be thicker if a widerfield of view is needed, or thinner if a closer working distance isneeded. The attachment section of the optical coupler can be a sleevecontinuous to the visualization section of the optical coupler. Thissleeve is slipped over the distal portion of the endoscope until theinner surface of the attachment section of the optical coupler makescontact with a lens of the endoscope. The elastic properties of thesleeve-like attachment section of the optical coupler, and its smallerinternal diameter provide a secure hold on the endoscope.

The optical coupler may have a hollow instrument channel or channelsthat extend through the visualization section of the optical coupler.The channel(s) can be the same diameter and align with the workinginstrument lumen(s) or channels(s) of the endoscope. This allows probesor instruments to be passed from the endoscope lumens or channelsthrough the visualization section of the optical coupler.

Often during endoscopic examinations and procedures, the tissue or anobject being viewed is or can be obstructed by blood or other opaquebodily fluids. With the optical coupler attached to the endoscope, theoptical coupler pushes through the opaque fluid, displacing it. Sincethe coupler is soft, contact can be safely made with the tissue orobject needed to be viewed. The optical coupler, with slightcompression, will keep in contact with the tissue and because thevisualization section of the optical coupler is clear, visibility is notimpeded thereby providing a clear view to image with the endoscope.

The object being viewed may have steep undulations. In one embodiment ofthe coupler, a very low durometer (soft) surface of the coupler conformsto the shape of the object.

The coupler has a very elastic nature so vibrations and movements of theendoscope are dampened, also improving the ability to visualize. Theoptical coupler's soft, flexible, elastic properties will cause minimaldeformation or damage to soft tissue. Additional force beyond what isneeded to displace the opaque fluid can be applied to the endoscope toflatten or unfold tissue that may be in a contracted state. This wouldreveal areas of the tissue that would not be seen without the coupler.In another embodiment, the coupler can be comprised of a high durometer(stiff) material to allow the tissue to conform to the shape of thecoupler. Because the tissue conforms to the shape of the coupler, fluidsare displaced and allow clear visualization. In both embodiments,medical instruments can be passed through the aligned working instrumentlumen(s) of the endoscope and instrument channel(s) of the coupler,making surgical repairs, taking biopsies, etc., possible with endoscopicinstruments and methods.

Depending on the endoscopic procedure, the optical coupler propertiesmay vary. For example, a high tensile strength and high tear resistancefor the coupler material may be suitable. In certain applications, atotally elastic material that provides an elastomeric coupler may bebeneficial.

Couplers composed of hydrophobic materials may be the best choice foruse in a water or blood environment. For example, a coupler composed ofsilicone material repels blood, staying clear for extended periods ofuse, additionally the silicone repels lipids. The coupler, or a portionof the coupler, being composed of a hydrophobic substance will not swellfrom the uptake of water or fluids in its working environment.

In an oil, grease, and water environment, a coupler coated with a superhydrophilic would be advantageous. After the coupler has an initialexposure to water, water molecules push away other molecules, gainingaccess to the surface of the coupler forming stable hydrogen bonds thatare reluctant to break. This keeps contaminants away from the coupler soit remains clear longer.

Couplers composed of hydrophilic materials may be advantageous in thecoupler. If the coupler or portions of the coupler are composed of ahydrophilic substance, it will swell in its working environmentincreasing the area of displacement or swell to a predetermined shape.

High thermal resistance can be beneficial in the material of thecoupler. For example, the material will not melt with heat (e.g., 500°F.-1200° F.) from electrocautery or radio ablation procedures.Electrical isolative, high corona resistance materials are alsobeneficial when the coupler is used in electro, radio frequency,cautery, or harmonic scalpel procedures.

The coupler also provides for various safety improvements in endoscopicprocedures. In both laparoscopic and general surgery, smoke emitted fromthe burning tissue while using electro cauterization instruments oftencause poor or zero visibility in the surgical field. The procedures mustbe stopped until the smoke is dissipated. When the electro cauterizationis used in conjunction with the coupler constant visualization of thetissue remains, the coupler displaces the smoke. The coupler can bedimensioned so that it is soft with no sharp edges to cause dissections.The coupler can be dimensioned with a larger surface area to dissipateforce when an endoscope is pushed forward in a body lumen. The coupleris dimensioned with a large outer surface area as compared to theobjective lens of the endoscope. This is advantageous as one small dropof blood can totally obscure vision from an endoscope objective lens.Small drops of blood on the outer surface of coupler will only partiallyobscure visibility. The coupler can be dimensioned with a domed shape,smooth slippery outer surface that will allow better maneuvering intube-like structures such as the esophagus, colon, veins, and arteries.The coupler also corrects wide-angle curvature created by the commonlens used on videoscopes.

The coupler gel can be composed with a variety of materials includingpolydimethylsiloxane, hydrogels, polyurethanes, albumin based gels,mineral oil based gels, polyisoprene, polybutadiene, or other clearcomposite. One preferred material is polydimethylsiloxane because of itsbiocompatibility in medical applications, low price, and it is easy tomold and cure. Clear, flexible hydrogels that have extreme resistance totearing are another preferred material.

The material used to form the optical coupler can be comprised of two ormore compounds, for example an opaque compound attaches and holds twovisualization portions of a coupler in position, the first visualizationportion is an inner clear semi rigid compound shaped to match the fieldof view and minimum depth field of the imaging system, and the secondportion is attached to the outer boundary of the first visualizationportion and is composed of very soft gel providing additional area offluid displacement for maneuvering and positioning instruments underdirect vision. Methods described in U.S. Pat. Nos. 7,235,592 and7,205,339 can be utilized to produce a coupler with portions or areas ofthe gel with different physical properties.

The devices described herein can be used in various applications. WithNatural Orifice Translumenal Endoscopic Surgery (NOTES), the couplerenables procedures to continue when unexpected bleeding or other fluidssuch as bile or stomach contents obstruct the view. Also, the couplercan create or increase working space by pushing organs out of the fieldof view. With a laryngoscope in trauma and emergency situations, thecoupler would push blood, foreign objects or food away to increasevisibility to allow visualizing of the trachea. When taking biopsies isrequired, the coupler isolates the intended biopsy target, the tumor orarea to be biopsied from surrounding tissue. Close focusing and contactwith the tissue with the aid of the coupler can improve reliability byallow multiple biopsies to taken in exact locations defining borders ofthe tumor, and minimize tumor cells from entering the blood stream orlymph channels. A cautery probe or electrode can be used simultaneouslyor in conjunction with the biopsy forceps, minimizing bleeding andlength of procedure.

The coupler can be used in various endoscopic intra-cardiac proceduressuch as: (1) myocardial biopsy (for transplant monitoring or tumorsampling); (2) valve repair or reconstruction; (3) patent foramen ovale(PFO) closure; (4) ventricle septal defect (VSD) closure; (5) pacingwire placement or removal; (6) stem cell injection; (7) coronary sinuscannulations (8) and maze procedure. In cryoablation, a specializedcomposite coupler could be made that has warming channels to warm theexternal surface of the coupler to protect surrounding tissue fromfreezing. In radiofrequency ablation, insulating and isolatingproperties of the coupler would concentrate power, protectingsurrounding tissue.

The coupler can be used in various vascular procedures. The coupler canbe used to guide proper placement of covered stents in dissected aortas,or visualize an intra-vascular laser. The coupler could be used toinspect the suture line of a large or small vessel anastomosis toevaluate the quality of the suturing and or determine the location ofany bleeding.

In certain surgical or trauma situations there is severe arterialbleeding from a wound or vessel. Often the first action taken is tocompress a finger or sponge on the area of bleeding. After time passesthe finger or sponge is removed. If the bleeding continues either morecompression or other actions are taken such as blind clamping,suctioning the blood away and then clamping and suturing, or homeostaticmaterials are applied. Blood loss can be substantial.

An embodiment mounted at the end of a finger shaped wand can becompressed over a bleeding site, both clearing the field of blood andcreating a view to locate the point of bleeding. Since the coupler isclear, soft and biocompatible, a suture or staple can be passed thoughthe coupler to repair the bleeding site.

The coupler is also beneficial in non-medical applications. Embodimentsof the coupler can be attached to the distal end (objective lens) of aborescope or attached to micro or conventional video cameras, inspectionscopes, or still cameras. This allows viewing and/or making repairsinside pipes, holding tanks, containers, etc when the fluid is opaque,such as petroleum products, sewerage, food products, paint, etc,eliminating the need to empty the pipes or containers (e.g., oil tanks)The size of the coupler or the amount of flexibility can be scaled forspecific applications, for example, displacing large volumes of fluidwhen examining large areas. The shape of the coupler can be generallyflat, convex (with varying levels of curvature), or shaped for specifictasks. For example, the coupler may be shaped as a square, or as anangular shape to displace opaque fluids in the corners of a tank toinspect the seams. Examination of joints, welds, seams for corrosion orcracks could be performed in pipes that contain moving fluid. A couplercould be used in conjunction with a video camera and a robotic vehicleto view remote locations. Large couplers with large working channelswill allow devices to be passed though a coupler to make repairs usingscrews, adhesive patches, etc. The coupler can be formed from materialsthat resist acid, alkalinity, high heat, or viscosity of the fluid beingdisplaced by the coupler. As opposed to medical usage (disposable,single use), the coupler preferred embodiment with industrialapplications would be reusable.

The working channels within the coupler or parallel to the coupler allowsurgical instruments, probes, biopsy needles, needles, sutures etc. tobe passed to the area being viewed. Since the coupler is flexible, thechannels can move within or around the coupler without compromising itsfunction. One enabling property of the coupler is its soft flexibleshape that conforms to the tissue or object being viewed. Thischaracteristic reduces damage to delicate tissues or structures.

Another advantage of the coupler is that only the specific area beingviewed through the coupler attached to the endoscope requiresillumination and therefore, the targeted view requires less light to besupplied by the endoscope lighting system. Because the number of lightfibers required for illumination is less, endoscopes can be smaller orless expensive to manufacture. Also, since it is only necessary toilluminate the area of the coupler at its outer boundary, endoscopes ofsmaller diameter would be required to view a targeted area.

An external light source for the endoscope can increase thefunctionality of the coupler. When the coupler does not contact thesurface of tissue in a large chamber, such as the stomach inflated withair, light emitting from the distal end of the endoscope can bereflected from the outer surface of the coupler back to the camera lens,degrading the endoscope view. Using an external light source and turningoff the endoscope light source reduces the reflection.

Alternatively, a light fiber placed through the instrument channel whichstops at the outer boundary will provide lighting while viewing objectsin the inflated stomach. After the coupler contacts the tissue coveredby opaque fluid or blood, the external light is shut off or the lightfiber is withdrawn from the instrument channel.

The coupler can be a semi-solid gel, which is transparent and flexible,that attaches to a wide variety of endoscopes. For minimally invasiveprocedures, the smallest possible scope is used. The optimal shape andsize of the coupler can be determined by the field of view of theendoscope, or conversely an endoscope can be chosen that will match thesize and shape of the coupler. The shape of the coupler can bemanufactured with a preformed shape matched to the contour of the objectthat will be examined, for example an endoscope coupler could be made inthe shape of the blood pool at the apex of the heart. This coupler canbe used in conjunction with a 2 mm angioscope maneuvered into the apexof the heart and displace the blood to visualize the inside wall of theventricle of the beating heart.

The coupler can be attached to the endoscope with a clear adhesivematerial. The coupler can be attached as a screw on auxiliary lens orfilter allowing different couplers with different purposes or functionsto be utilized with the same scope. The coupler can be attached and heldin place with suction. The coupler can be attached by sewing on withsutures. The coupler can be attached with wire, nylon or other braidmaterial. The coupler can be attached to endoscopes with mesh or pliablemembranes. When using a mesh net to attach the coupler to the endoscope,gel strength and viscosity must be high enough to prohibit gel flowthrough holes in the outer layer of mesh.

A coupler can be compressed in a tube fixed to the end of the scope. Acoupler attached to the endoscope can be compressed in a retractablesheath.

The coupler can be made in situ by injecting an optical fluid (e.g., asiloxane polymer) and a cross linking agent (e.g., a multifunctionalsilane) into two separate lumens of the endoscope. The liquid componentscombine and crosslink to form a cured viscoelastic solid (e.g., asilicone gel or silicone elastomer) inside a pliable membrane attachedto the distal end of the scope. The solid body of the coupler can bereinforced with micro thin strands of biocompatible fibers, carbonfiber, Nitinol, suture materials, and/or light fibers. In situ formationof the coupler allows a larger coupler to be formed inside the body,increasing the area of visibility. The coupler can be chemically ormechanically dissolved for removal after use.

If the coupler is confined inside a balloon, membrane, mesh or atube-like structure with higher wall tension than the systolic bloodpressure, tunnels formed by moving the instruments, probes, needles orother devices within the coupler will be refilled with gel keeping thegel transparent. To keep the gel contained within the coupler wouldrequire a gel strength high enough to prohibit flow through holes madein the outer balloon, membrane or mesh by the needles or devices.

Embodiments of the coupler can have one, two or more working channelsthat align with the endoscope's working lumens. Other versions of thecoupler allow for additional internal channels or along the edges of thedevice for use in more complex procedures, such as suturing.

The coupler can be used in any minimally invasive procedure. Biopsies inthe body, for example, could be taken under direct view, reducing theneed for CO₂ inflation. The coupler allows exact placement of needlesand medical devices in situations where active bleeding or other bodilyfluids impede visibility. The coupler can be held with pressure over anactive bleeding site to stop bleeding until the suturing process,stapling, clamping or medical device placement is complete.

Other instruments or devices can be pushed through the coupler, notcompromising its form or transparency. Channels are created by piercingthe coupler with needles, probes or instruments and the channel willreseal as the medical instruments are withdrawn.

Attaching the coupler to endoscopes that contain working lumens, thecoupler and endoscope work in unison. Transparent or semi-transparentsoft flexible tubes are passed though these channels penetrating thecoupler, creating continuous channels that allow probes to be passed tothe targeted area. These probes may include sensors, hypodermic needles,instruments, light fibers or medical devices that can be passed in andout of the coupler to exact repeatable positions.

Fixed channels external to the endoscope can be added to steer or directprobes around the coupler to be seen and maneuvered within the viewingarea. The device could be fixed to a 45 degree scope or mirror set 45degrees to a lens to permit viewing from the side of a scope. Thisallows viewing of the side of vessels or tube as the scope is pushedforward. When used in conjugation with wide angle optics, the coupleryields a circumferential view in a pipe or vessel.

Turning now to FIGS. 1-3, there is shown a first example embodiment ofan optical coupler 10. The optical coupler 10 includes a visualizationsection 12 at a distal end 13 of the optical coupler 10. Thevisualization section 12 has a generally slightly curved, convex outersurface 14 that extends from a first outer side boundary 15 to a secondopposite outer side boundary 16 of the optical coupler 10. The outersurface 14 may be constructed to be generally flat, but a curved outersurface 14 is preferable because the curvature helps to clear the fieldof view by pushing any fluid or matter from the center of the outersurface 14 to the outer boundaries 15, 16. A flat outer surface 14 maybe more difficult to clear since the pressure is equal across the entirearea of contact and fluid can become trapped between the lens and asurface in which it is desired to view or perform work. A curved outersurface 14 is also preferable to correct any curvature distortioncreated by an objective lens 40 that may be used in conjunction with thecoupler 10. The optical coupler 10 has a proximal surface 18, and ahollow instrument channel 19 extends from the proximal surface 18 towardthe outer surface 14.

The hollow instrument channel 19 may be constructed such that thechannel 19 does not extend all the way through the visualization section12 to the outer surface 14. In such a case, a barrier section 20 ofmaterial is provided between a distal end 21 of the hollow instrumentchannel 19 and the outer surface 14 of the optical coupler 10.Alternatively, the instrument channel 19 may extend the full length ofthe visualization section 12, extending through the optical coupler 10,as shown in FIGS. 8 and 9. Such a configuration may allow for the freeand unencumbered exchange of instruments. A water tight seal or valve29, such as a Tuohy-Borst type valve, may be employed on the proximalend 17 of the endoscope instrument channel 19 to prevent or minimizeair, fluid, and/or foreign matter from flowing through the instrumentchannel 19.

While an instrument channel 19 is shown in the optical coupler 10 ofFIGS. 1-3, the visualization section 12 may be constructed without aninstrument channel 19. In such a case, instruments may be passeddirectly through the visualization section 12 as the visualizationsection 12 may be constructed of a material that is self-sealing andelastic enough to permit instruments to be passed through the entirelength of the visualization section 12 of the optical coupler 10. Anexample of an optical coupler 10 without an instrument channel 19 isshown in FIGS. 10 and 11, and is described in more detail below.

The optical coupler 10 also includes an attachment section 22 connectedto and extending away from the visualization section 12. The attachmentsection 22 is at the proximal end 23 of the optical coupler 10. Theproximal end 23 of the optical coupler may be angled to lessen thechance that the optical coupler 10 may catch on any surfaces when theoptical coupler 10 is being removed from its environment of use. In theembodiment shown, the attachment section 22 is in the form of acylindrical wall 24. The proximal surface 18 and the cylindrical wall 24of the optical coupler 10 define a hollow cylindrical opening 25 of theoptical coupler 10 within the sleeve-like cylindrical wall 24.

Referring to FIG. 3, the optical coupler 10 can be mounted on anendoscope 30. The endoscope 30 has a distal end 31 that is inserted inthe hollow cylindrical opening 25 of the optical coupler 10. In oneform, the cylindrical wall 24 of the coupler 10 has a diameter one tothree millimeters larger than the endoscope 30. The endoscope 30 has asheath 32 with an outer surface 33 that snugly engages the cylindricalwall 24 of the optical coupler 10. In a non-limiting example, the sheath32 has an outside diameter of 7-15 millimeters. An end surface 34 of theendoscope 30 sealingly engages the proximal surface 18 of the opticalcoupler 10. The endoscope 30 includes a first lumen 35 and a secondlumen 36 and a third lumen 37 that extend from the end surface 34 of theendoscope 30 to a proximal end (not shown) of the endoscope. Lumeninternal diameters of 2-4 millimeters are typical. A light guide 39 ispositioned in the first lumen 35 for transmitting light toward a surfacearea at or beyond the outer surface 14 of the optical coupler 10. Anobject lens 40 is positioned at a distal end of an image carrying fiber42, and the lens 40 is optically connected to the image carrying fiber42 for receiving light that has been reflected from the surface areabeing viewed. The object lens 40 and the image carrying fiber 42 arelocated in the second lumen 36. The third lumen 37 aligns with thehollow instrument channel 19 of the optical coupler 10 when the opticalcoupler 10 is mounted on the endoscope 30. In the embodiment shown, theinstrument channel 19 and the third lumen 37 have the same size innerdiameter within a tolerance of ±5%. The optical coupler 10 can alsoinclude a Light Emitting Diode (LED) 11 near the outer surface 14 of thecoupler to provide illumination prior to the coupler contacting anyfluids, tissue, or structure. The LED 11 may be provided power via awire (not shown) in the endoscope 30 or from an external source.

In one example configuration, the endoscope 30 may be a fixed-focusendoscope having a specific depth of field. The outer surface 14 may bespaced apart from the proximal surface 18 of the optical coupler 10 by alength D (see FIG. 1) equal to a reference distance selected from valuesin the depth of field distance range of the endoscope 30. In one exampleconfiguration, the endoscope 30 may have a depth of field in the rangeof 2 to 100 millimeters. In this case, the outer surface 14 is spacedapart from the proximal surface 18 of the optical coupler 10 by a lengthin the range 2 to 100 millimeters. Preferably, the length D equals areference distance that is in the lower 25% of values in the depth offield distance range of the endoscope 30. In one example configuration,the endoscope 30 may have a depth of field in the range of 2 to 100millimeters. In this case, the length D equals a value of 2-26millimeters. More preferably, the length D equals a reference distancethat is in the lower 10% of values in the depth of field distance rangeof the endoscope 30. In one example configuration, the endoscope 30 mayhave a depth of field in the range of 2 to 100 millimeters. In thiscase, the length D equals a value of 2-13 millimeters. Most preferably,the length D equals a reference distance that is greater than or equalto the lowest value (e.g., 2 millimeters) in the depth of field distancerange of the endoscope 30. In one version of the coupler 10, the lengthD is 7-10 millimeters, or a typical distance that the endoscope 30 isheld from tissue that would be receiving an endoscopic treatment ortherapy.

The design of the length D for the optical coupler 10 should also takeinto consideration the characteristics of the materials that compose thecoupler 10, such as any possible compression of the coupler 10 when itis held against a surface. For example, if the coupler 10 may becompressed 1 millimeter when held against a surface and the lowest valuein the depth of field distance range of the endoscope 30 is 2millimeters, then the length D should be greater than or equal to 3millimeters to compensate for this possible compression.

The optical coupler 10 can be formed from a variety of materials. In oneversion of the optical coupler 10, the optical coupler 10 is molded froma material selected from silicone gels, silicone elastomers, epoxies,polyurethanes, and mixtures thereof. The silicone gels can be lightlycross-linked polysiloxane (e.g., polydimethylsiloxane) fluids, where thecross-link is introduced through a multifunctional silane.

The silicone elastomers can be cross-linked fluids whosethree-dimensional structure is much more intricate than a gel as thereis very little free fluid in the matrix. In another version of theoptical coupler 10, the material is selected from hydrogels such aspolyvinyl alcohol, poly(hydroxyethyl methacrylate), polyethylene glycol,poly(methacrylic acid), and mixtures thereof. The material for theoptical coupler 10 may also be selected from albumin based gels, mineraloil based gels, polyisoprene, or polybutadiene. Preferably, the materialis viscoelastic.

Turning now to FIGS. 23a and 23b , fully functional couplers 10 can bemade by combining an uncured silicone material with an additive/heatcuring agent. Various silicone material and additives can be used toproduce couplers of differing degrees of softness. The material can bepremixed in a 20 cc vial and placed in a vacuum chamber to remove airentrained in the silicone during the mixing process. Next, the siliconeis poured into a chamber 1101 of Part A of a four piece mold 1100 andplaced in the vacuum chamber if any bubbles were visible. After thesilicone material in Part A was clear, Part B of the mold was screwed toPart A via threading 1102, 1103 on Parts A and B, respectively. Thechamber 1104 in Part B is then filled and de-bubbled as described forpart A. Mold parts C and D are pre assembled using a set screw 1105 toensure the resulting lens have the proper shape. The leading portion1106 of assembled Part C/D is dipped in the silicone material, thencentered over the silicone in Part AB with the aid of the alignment pins1107 and dropped and or pushed downward in respective holes 1108 untilfull seated against Part B. The leading portion 1106 includes aninstrument channel pin 1109 to form an instrument channel in thecoupler. The assembly is cured in an oven at 90° C. for at least onehour. After curing, the mold 1100 is disassembled by unscrewing Part Afrom Part B, pulling Part C/D from Part B. A thick walled polyvinyl tube(not shown) can be placed over the outer surface of the coupler, afterapplying a vacuum to the tubing the coupler is pulled out of Part B.

Referring back to FIGS. 1-3, in the optical coupler 10, the material isoptically clear such that the light guide 39 can transmit light throughthe optical coupler 10 toward a surface area at or beyond the outersurface 14 of the optical coupler 10 and such that the optical coupler10 is capable of transmitting an optical image of the surface area beingviewed back to the lens 40. In one version of the optical coupler 10,the material has a degree of light transmittance greater than 80% basedon test standard ASTM D-1003 (Standard Test Method for Haze and LuminousTransmittance of Transparent Plastics). In another version of theoptical coupler 10, the material has a degree of light transmittancegreater than 90% based on test standard ASTM D-1003. In another versionof the optical coupler 10, the material has a degree of lighttransmittance greater than 95% based on test standard ASTM D-1003. Inanother version of the optical coupler 10, the material has a degree oflight transmittance greater than 98% based on test standard ASTM D-1003.Preferably, the material has an optical absorption of less than 0.1% inthe visible light range, and more preferably the material has an opticalabsorption of less than 0.01% in the visible light range. The materialhas an index of refraction of about 1.3 to about 1.7, and preferably,the index of refraction of the material matches the index of refractionof the light guide 39, or is as low as possible.

The optical coupler 10 may also be coated with different materials toreduce the amount of adherence properties. Additionally, some coatingsof the optical coupler 10 improve with light reflections. Samplecoatings that may be used on the optical coupler include thermoplasticfilm polymer based on p-xylylene such as Parylene C, which is anoptically clear biocompatible polymer having abrasion resistant andhydrophobic properties.

The hardness of the material of the optical coupler 10 can be varieddepending on the application. If the surface being viewed has steepundulations, a very low durometer (soft) surface of the coupler willform to the shape of the object. Alternatively, the coupler couldcomprise a high durometer (stiff) material to allow the tissue toconform to the shape of the coupler. In one form, the material has adurometer ranging from 2-95 on the Shore 00 scale. In another form, thematerial has a durometer ranging from 2-20 on the Shore 00 scale. Inanother form, the material has a durometer ranging from 40-80 on theShore 00 scale. In another form, the material has a durometer rangingfrom 60-80 on the Shore 00 scale. As alluded to above, the material insome applications may preferably have a durometer outside of the rangesof the Shore 00 scale just discussed. Although materials having ahardness of 80 or more on the Shore 00 scale may not technically beconsidered a “gel”, this specification generally refers to the materialsthat can compose the coupler 10 by using the term “gel.” The use of theterm “gel” is not meant to limit the devices described herein tospecific materials or specific ranges of hardness on the Shore 00 scale.

Turning now to FIGS. 4-6, there is shown a second example embodiment ofan optical coupler 210. The optical coupler 210 can be formed from anyof the same materials as the optical coupler 10. The optical coupler 210includes a visualization section 212 at a distal end 213 of the opticalcoupler 210. The visualization section 212 has an outer surface 214 witha greater degree of curvature than the embodiment shown in FIGS. 1-3.The convex, generally dome shaped outer surface 214 extends from a firstouter side boundary 215 to a second opposite outer side boundary 216 ofthe optical coupler 210. The optical coupler 210 has a proximal surface218, and a hollow instrument channel 219 extends from the proximalsurface 218 toward the outer surface 214. A barrier section 220 ofmaterial is provided between a distal end 221 of the hollow instrumentchannel 219 and the outer surface 214 of the optical coupler 210.Preferably, all of the visualization section 212 (other than the hollowinstrument channel 219) is a non-porous solid viscoelastic material.

The optical coupler 210 also includes an attachment section 222connected to and extending away from the visualization section 212. Theattachment section 222 is at the proximal end 223 of the optical coupler210. In the embodiment shown, the attachment section 222 is in the formof a cylindrical wall 224. The proximal surface 218 and the cylindricalwall 224 of the optical coupler 210 define a hollow cylindrical opening225 of the optical coupler 210.

The optical coupler 210 can be mounted on an endoscope 30. The endoscope30 has a distal end 31 that is inserted in the hollow cylindricalopening 225 of the optical coupler 210. The endoscope 30 has a sheath 32with an outer surface 33 that snugly engages the cylindrical wall 224 ofthe optical coupler 210. An end surface 34 of the endoscope 30 sealinglyengages the proximal surface 218 of the optical coupler 210. Theendoscope 30 includes a first lumen 35 and a second lumen 36 and a thirdlumen 37 that extend from the end surface 34 of the endoscope 30 to aproximal end (not shown) of the endoscope. A light guide 39 ispositioned in the first lumen 35 for transmitting light toward a surfacearea at or beyond the outer surface 214 of the optical coupler 210. Anobject lens 40 is positioned at a distal end of an image carrying fiber42, and the lens 40 is optically connected to the image carrying fiber42 for receiving light that has been reflected from the surface area.The object lens 40 and the image carrying fiber 42 are located in thesecond lumen 36. The third lumen 37 aligns with the hollow instrumentchannel 219 of the optical coupler 210 when the optical coupler 210 ismounted on the endoscope 30. In the embodiment shown, the instrumentchannel 219 and the third lumen 37 have the same size inner diameterwithin a tolerance of ±5%.

The endoscope 30 can have a field of view of A degrees (e.g., 90-170°)as shown in FIG. 4. In FIG. 4, a portion of the outer surface 214 of thevisualization section 212 is dome-shaped, and the portion of the outersurface 214 of the visualization section 212 that is dome-shaped iswithin the field of view of the endoscope 30. This provides for improvedimaging with an increased working space as organs can be pushed out ofthe field of view.

Still referring to FIGS. 5 and 6, after the physician mounts the opticalcoupler 210 on the endoscope 30, the endoscope is inserted into a bodycavity 51. The optical coupler 210 is placed in contact with a region 52of the wall 54 of the body cavity 51 thereby displacing opaque fluidand/or particulate matter in contact with or adjacent the region. Lightis transmitted from a light source through the light guide 39 in aconventional manner. The light then passes through the optical coupler210 and onto the region 52. Reflected light then passes back through theoptical coupler 210 and the lens 40 receives the reflected light fromthe region 52. The lens 40 transmits an optical image to the imagecarrying fiber 42 which transmits the optical image to an eyepiece orvideo display in a conventional manner.

The physician then inserts a medical instrument 60 in direction B (seeFIG. 5) in the third lumen 37 of the sheath 32 of the endoscope 30. Themedical instrument 60 is passed through the instrument channel 219 inthe coupler 210 and then the medical instrument 60 is pierced throughthe barrier section 220 and the outer surface 214 of the coupler 210. Amedical procedure can then be performed using the medical instrument 60on the region 52 of the wall 54 of the body cavity 51. Non-limitingexamples of the medical instrument 60 include a biopsy forceps, anelectrocauterization device, an ablation device, and a suturing orstapling device. Optionally, viewing optics can be pierced through thebarrier section 220 and the outer surface 214 of the coupler 210.

Turning now to FIG. 7, there is shown a third example embodiment of anoptical coupler 310. The optical coupler 310 can be formed from any ofthe same materials as the optical coupler 10. The optical coupler 310can be mounted on an endoscope 30. The optical coupler 310 includes avisualization section 312 at a distal end 313 of the optical coupler310. The visualization section 312 has a generally dome shaped outersurface 314 that extends from a first outer side boundary 315 to asecond opposite outer side boundary 316 of the optical coupler 310. Theoptical coupler 310 has a proximal surface 318, and a hollow instrumentchannel 319 extends from the proximal surface 318 toward the outersurface 314. The optical coupler 310 also includes an attachment section322 connected to and extending away from the visualization section 312.The attachment section 322 is at the proximal end 323 of the opticalcoupler 310. In the embodiment shown, the attachment section 322 is inthe form of a cylindrical wall 324. The proximal surface 318 and thecylindrical wall 324 of the optical coupler 310 define a hollowcylindrical opening 325 of the optical coupler 310.

In the optical coupler 310, a narrowed passage 373 is provided at thedistal end 321 of the hollow instrument channel 319. A self-sealingmembrane 371 seals the narrowed passage 373 of the hollow instrumentchannel 319. The membrane 371 can be pierced by the medical instrument60 and the membrane 371 reseals after withdrawal of the instrument 60from the membrane 371.

Turning now to FIGS. 10 and 11, an optical coupler 10 similar to thecoupler displayed in FIGS. 1-3 is shown, however, the coupler 10 doesnot have an instrument channel 19 and has an electrocauterization device75. The electrocauterization device 75 in the optical coupler 10includes a wire 27 extending through the visualization section 12 whichconnects with an electrode 26 on the outer surface 14. The wire 27 andelectrode 26 may be molded into the materials forming the opticalcoupler 10 during the manufacturing process of the coupler 10. Otherinstruments may also be molded into the optical coupler 10 in thisfashion as well. Doing so would provide an optical coupler 10 that issimple and inexpensive to manufacture, as well as a coupler 10 with alesser chance that air, fluid, and/or foreign matter from thesurrounding environment will enter the coupler 10 when it is attached toan endoscope, camera, or other device. Instead of molding the wire 27and electrode 26 into the coupler 10, the wire 27 and electrode 26 maybe delivered through the visualization section 12 of the coupler 10after the coupler 10 is formed, due to the properties andcharacteristics of the coupler 10. Of course, instruments other than orin addition to the electrocauterization device 75 may be deliveredthrough the coupler 10 when the coupler 10 does not have an instrumentchannel 19.

However, the wire 27 attached to the electrode 26 may also be configuredin an optical coupler 10 that also includes one or more instrumentchannels 19. The wire 27 may be embedded in the visualization section 12and run parallel and close to the hollow instrument channel 19.Alternatively, the wire 27 may pass through the visualization section 12in an instrument channel 19.

In one non-limiting example coupler for use in endoscopicgastrointestinal procedures, the durometer of the coupler is about 15 ona Shore 00 scale, if the tissue is delicate. Necrotic friable tissuerequires a softer durometer and therefore, a durometer less than 6 maybe desired. The coupler requires enough compression and flexuralstrength to displace fluids. If examining a stomach with multi folds, adurometer of 50 on a Shore 00 scale may be desirable. The coupler shouldhave optical clarity in the visible light range 400-750 nanometers. ForPhotodynamic Therapy, IR or florescence studies different ranges oflight transmission, absorption or refraction may be beneficial.

Other non-limiting example specifications for a coupler used as anadjunct for gastrointestinal procedures are as follows: Biocompatible,single use; or made for multiple uses. Flexibility: durometer range from2-80, Shore 00 scale; Minimal optical absorption (<0.1%); Index ofrefraction: approximately 1.40-1.50, but may be matched to the endoscopelight transmission, water, air, or whatever Index of refraction bestsreduces lens surface reflections; Tensile strength: minimum, strongenough to displace fluid and tough enough to resist tearing; Elastic andself-sealing; Hydrophobic: surface repellant; Hydrophilic: within thematrix structure; High thermal resistance: will not melt with heat (500°F.-1200° F.) from electrocautery or radio ablation; and Autoclavable: at250° F.-273° F.

Turning now to FIGS. 12a-12c , another embodiment of an optical coupler410 is shown mounted on an endoscope 30. The optical coupler 410 can beformed from any of the same materials as the optical couplers previouslydescribed 10, 210, 310. The optical coupler 410 includes a visualizationsection 412 with a first outer boundary 415 and a second outer boundary416 and a hollow instrument channel 419 that extends through thevisualization section 412 to an outer surface 414. As shown in FIGS.12a-12c , the first and second outer boundaries 415, 416 extend at anangle a from the outer surface of the endoscope 30.

A biopsy forceps 60 is inserted into a first lumen 35 in the endoscope30 and is passed through the instrument channel 419 in the opticalcoupler 410. The endoscope 30 may be configured to have other lumens asdescribed in previous embodiments. In FIG. 12a , the jaws 61 of thebiopsy forceps 60 are opened near the outer surface 414 of thevisualization section 412. Because the visualization section 412 iscomposed of elastic materials, the visualization section 412 may expandwhen the jaws 61 are opened to take a biopsy sample of tissue from awall 54 of the body cavity 51, as illustrated in FIG. 12a . The forceps60 cannot be opened in the fixed diameter of the lumen 35 of theendoscope 30. When the jaws 61 of the forceps 60 are opened, the hingedjaws 61 can trap material comprising the coupler 410, possibly hinderingfunctionality of the forceps 60. To alleviate this hindrance, theinstrument channel 419 may be lined with a clear, flexible tube 419 aand/or the jaws 61 of the forceps 60 may be covered with a soft,flexible sleeve 61 a, as illustrated in FIG. 12 d.

The biopsy sample is captured and removed from the wall 54 of the bodycavity 51 as shown in FIGS. 12b and 12c . FIG. 12b shows the jaws 61 ofthe biopsy forceps 60 closing and taking a biopsy sample of tissue froma wall 54 of the body cavity 51. Then, as shown in FIG. 12c , the biopsyforceps 60 with the biopsy sample may be removed from the endoscope 30by passing through the instrument channel 419 and the lumen 35. Afterthe biopsy sample is withdrawn and inspected, the instrument channel 419can be used to place a coagulation device at the exact biopsy site onthe wall 54 or to reinsert the biopsy forceps 60 to obtain an additionalbiopsy sample.

Other types of biopsy forceps and graspers that can be used with thecouplers described herein include, but are not limited to: oval cups,long oval cups, long oval cups with spike, serrated cups, serrated cupswith spike, alligator graspers, elongated rat tooth “stent remove”, rattooth graspers, three nail graspers, tripod graspers, fork 1×2 graspers.Of course, other medical tools 60 other than biopsy forceps and grasperscan be used with the couplers described herein.

As previously mentioned, the optical coupler could be used innon-medical applications. FIGS. 13-15 show two such examples ofenvironments and applications of where the optical coupler may beemployed.

Turning first to FIGS. 13a and 13b , an optical coupler 510 is shownmounted to a borescope 77. The optical coupler 510 may be used forinspecting surfaces or objects covered by opaque liquids or particulatematerials. The optical coupler 510 can be formed from any of the samematerials as referenced for the optical couplers previously described10, 210, 310, 410.

The optical coupler 510 has a visualization section 512 that has a firstouter boundary 515, a second outer boundary 516, and an outer surface514 that extends continuously from the first outer boundary 515 to thesecond outer boundary 516. The first and second outer boundaries 515,516 extend outwards from the borescope 77 at an angle, similar to theboundaries 415, 416 shown in FIGS. 12a-12c above. The outer surface 514is angled, such that it is composed of a first segment 514 a and asecond segment 514 b. If desired, the optical coupler 510 may beconfigured with other features as previously described, such as aninstrument channel.

As shown in FIG. 13b , the optical coupler 510 is designed such that thefirst and second segments 514 a, 514 b of the outer surface 514 willdisplace opaque liquid or particulate materials in a corner of twoplates 78, 80 that may render viewing the plates 78, 80 difficult. Thiscoupler 510 design may be beneficial for viewing a weld 82 betweenplates 78, 80, or for viewing the surfaces of the plates 78, 80 fordefects. Of course, the optical coupler 510 may be configured with otherfeatures, as previously described.

FIGS. 14a, 14b, 15a, and 15b depict an optical coupler 610 mounted on acamera 84. As shown in FIG. 14a , the camera 84 has a lens 85 and maytake still images, videos, or both. The optical coupler 610 can beformed from any of the same materials as referenced for the opticalcouplers previously described 10, 210, 310, 410, 510. The opticalcoupler 610 has a visualization section 612, a first outer boundary 615,a second outer boundary 616, and an outer surface 614 that extendscontinuously from the first outer boundary 615 to the second outerboundary 616. A light ring 686 is attached to an outer surface 87 of thelens 85 of the camera 84, near the proximal end 623 of the coupler 610.As shown in FIG. 15a , the optical coupler 610 may also include aninstrument channel 619 such that a semi rigid tube 88 may be placedparallel to or through the camera 84 and through the instrument channel619. Alternatively, the coupler 610 may not have an instrument channel619 and the tube 88 may be pierced through the visualization section612. The tube 88 may extend to the outer surface 614 of the opticalcoupler 610.

As shown in FIGS. 14b and 15b , the camera 84 and optical coupler 610may be placed in a pipe 90 that is filled with an opaque liquid 91, suchas oil. The camera 84 may be moved through the use of motorized platform92 to view the internal surface 93 of the pipe 90 to search for defects94. As shown in FIG. 15b , the semi rigid tube 88, fixed parallel to thecamera 84 and placed through the coupler 610, may be used to deliveradhesives, cements, or the like to the defect area 94 to repair thedefect.

Another optical coupler 710 is shown in FIG. 16. The optical coupler 710is mounted on an endoscope 30. A first lumen 35 of the endoscope 30aligns with an instrument channel 719 in the coupler 710. A second lumen36 provides access for an image carrying fiber 42 connected to a lens40, which contacts the coupler 710. A third lumen 37 provides anauxiliary fluid channel 41 in the endoscope 30. A nozzle 43 is providedat the distal end of the auxiliary fluid channel 41. The optical coupler710 includes an annular chamber 45 that can receive fluid 47 from theauxiliary fluid channel 41 and nozzle 43, and allow the fluid to passthrough the instrument channel 719 in the coupler 710. Fluid 47 can be aclear fluid, such as a water or saline to rinse away debris in the fieldof view or to clean the outer surface 714 of the coupler 730.

FIGS. 17a-17c illustrate a coupler 810 having a concave outer surface814 and a first lumen 835 that is mounted to an endoscope 30. As shownin FIGS. 17a-17c , as the coupler 30 is moved toward the wall 54 of abody cavity 51, an opaque liquid 91 (such as trapped blood) can becometrapped between the outer surface 814 and the wall 54 and restrict thefield of view of the endoscope 30. The coupler 810 includes aninstrument channel 819 that is aligned with the first lumen 835. Thus,fluid 47 can be flushed through the endoscope 30 via the first lumen 835and through the instrument channel 819 in coupler 810. Although notshown, fluid 47 can alternatively and/or additionally be flushed throughthe endoscope 30 via an auxiliary fluid channel in the endoscope 30,similar to that as described above with respect to FIG. 16. When thepressure of the introduced fluid 47 exceeds the pressure exerted by thecoupler 810 against the wall 54 of the body cavity 51, the fluid 47 willflush the trapped opaque liquid 91 from the area between the outersurface 814 and the wall 54 to allow for unrestricted view of the wall54. Additionally, because the coupler 810 can be comprised of softmaterials, the coupler 810 can allow the endoscope 30 to view andperform activities on the wall 54 of the body cavity 51 with anunrestricted field of view with the application of less force beingapplied to the wall 54. With a gel lens attached to the endoscope,injection of a therapeutic can be accomplished after tissue contact.After the lesion has been cut free by an endoscopic tool such as anelectro cautery knife or wire snare, the detached lesion can be removedby applying suction through the instrument channel.

To facilitate attachment to an endoscope 30, the coupler 10 can bepackaged with a cap 70 as illustrated in FIGS. 18a and 18b . The cap 70can be secured over the coupler 10 as illustrated in FIG. 18a . The cap70 protects the coupler 10 from dust and finger prints when handling andthe cap preferably has a clear top 76. The cap 70 also includes a rod 74that extends away from the cap 70 in a direction opposite the cover 76.The rod 74 is used to align the coupler to the endoscope 30 and canenter the instrument channel 19 of the coupler 10. Once the cap 70 isplaced on the coupler 10, the o-ring 72 that resides in acircumferential groove 71 in the cap 70A can be slid down to thevisualization section 22 of the coupler 10 to assist in retaining thecoupler 10 on the endoscope 30. An alternative cap (not shown) for thecoupler 10 could be to shrink wrap clear plastic wrap over the coupler10 after the rod 74 has been placed through the instrument channel 19 ofthe coupler 10.

The couplers described herein can also be used with rigid endoscopes 30.As illustrated in FIG. 19, a coupler 10 is attached to a rigid endoscopehaving a 0° end surface 34 and a field of view A. Due to the opticalstructure of most rigid endoscopes, internal lumens for instruments orfluid channels are not possible. A channel 49 that runs parallel to theouter surface of the endoscope 30 can be attached to the endoscope,directed though the sides of the coupler 10, and exit at an angle thoughthe outer surface 14 of the coupler 10. Due to the angled nature of thechannel 49, instruments passed through the channel 49 may remain visibleby the operator and closer to the center of the filed of view A of theendoscope 30. If the endoscope 30 has an angled end surface 34, asillustrated in FIG. 20, the channel 49 may be straight in order toremain closer to the center of the field of view B of the endoscope 30.A small lens imbedded in the surface of the gel lens that contacts theendoscope fibers could re-aim the light or diffuse the light to reducesurface reflections on gel lens.

Turning now to FIG. 21, a coupler 910 can be comprised of more than onematerial. The coupler 30 can include a first lumen 35, a second lumen 36with an image carrying fiber 42 and a lens 40, and a third lumen 37. Thecoupler 910 can be include a clear plastic or glass lens 40 within thefield of view portion 981 of the coupler 910. The field of view portion981 of the coupler 910 is preferably 30-40 Shore on the 00 Scale and canbe used to reduce light loss, magnify, decrease magnification, redirectthe image, or change the focal length of the endoscope 30. Small lens ormirrors (not shown) placed in the coupler 30 near the endoscope lightlens 40 will re-aim the light output, reducing reflections in the fieldof view A or concentrate light within the field of view A. The coupler910 also includes an instrument channel portion 983, which is preferably6-15 Shore on the 00 Scale, and a structure portion 985, which ispreferably 80 or more Shore on the 00 Scale.

EXAMPLES

The following Examples have been presented in order to furtherillustrate the devices described herein and are not intended to limitthem in any way.

Example 1

A coupler in a shape similar to that of FIG. 4 was formed from Sylgard®184 silicone elastomer available from Dow Corning Midland, Mich. USA.This silicone has an index of refraction of 1.43, and a durometer ofabout 80 on the Shore 00 scale. A monopolar electro cauterization wirewas pre molded into the coupler and wire pulled through the endoscopeworking channel of a Pentax EG3430 11.4 mm gastroscope. The wire wasconnected to a Bovie electro cauterization unit. The coupler was slippedover the distal end of the gastroscope. In the open chest of a sheep,the colonoscope was advanced in blood approaching an area to be electrocoagulated and video images showed a yellow flame/spark fromelectrocautery with no smoke visible.

Example 2

A coupler in a shape similar to that of FIG. 4 was formed from Sylgard®184 silicone elastomer. The coupler was attached to the end of a PentaxEG3430 11.4 mm gastroscope. Suitable video images were obtained in anelectrocauterization procedure on a sheep esophagus wall.

Example 3

A coupler in a shape similar to that of FIG. 4 was formed from Sylgard®184 silicone elastomer. The coupler was attached to the end of a PentaxEG3430 11.4 mmgastroscope. Suitable video images were obtained in asheep stomach.

Example 4

A coupler in a shape similar to that of FIG. 4 was formed from Sylgard®184 silicone elastomer. The coupler was attached to the end of a Pentax2931 9.8 mm gastroscope. Suitable video images were obtained inside asheep inferior vena cava. The portal vein entrance into the vena cavawas indentified. A small thrombus was also identified.

Example 5

A coupler in a shape similar to that of FIG. 1 was formed from CuringGel OC-451A-LPH 15, a silicone-based optical curing gel available fromNye Lubricants, Inc., Fairhaven, Mass., USA. The silicone gel has anindex of refraction of 1.51, and a durometer of 15 on the Shore 00scale. The coupler was attached to the end of a Pentax 9.8 mmgastroscope. Suitable video images were obtained for a swine stomachwall.

Example 6

A coupler in the shape similar to FIG. 1 was formed from a polyvinylalcohol (PVA) solution in a mixed solvent consisting of water anddimethyl sulfoxide (DMSO). Suitable images were obtained inside theswine stomach.

Other working prototypes of couplers were made with: OCK-451-80,OCK-451-LPH, and OCK-451-LPH-15 silicone-based optical curing gelsavailable from Nye Lubricants, Inc.; curable dimethylvinyl-terminateddimethyl siloxane available as Dow Corning CY 52-276; hydro gel lens;transparent poly (vinyl alcohol) hydrogel; a two component, lowviscosity silicone compound available as Master Sil 151MED; and mineraloil and a powdered plastic.

Handheld Device

Turning now to FIGS. 22a and 22b , a handheld device 1010 is shown. Thehandheld device 1010 includes a handle 1012, a frame 1014, and a cavity1016 within the frame 1014. Within the cavity 1016 is a transparentsection 1018 that is puncturable, or easily pierced, with surgicalinstruments. The transparent section 1018 can be comprised of similarmaterials as described above with respect to the optical couplers, andprovides many of the same benefits and advantages as described above.

The handheld device 1010 may be used in a variety of circumstances. Forexample, the handheld device 1010 may be used to push aside an opaqueliquid 91, such as blood, from the wall 54 of a body cavity 51, such asnear a laceration in the skin of a patient. In doing so, the transparentsection 1018 allows the physician to view the wall 54 of the body cavity51. The pressure of the transparent section 1018 may also helpcoagulation. The upper and lower surfaces 1020, 1022 of the transparentsection 1018 may be slightly convex as shown, flat, or concave asdescribed above with respect to the couplers, or provided in any otherdesired shape. Because the transparent section 1018 can be pierced, amedical tool 60 (such as a stapler) may pass through the transparentsection 1018, allowing the physician to treat the wall 54 of the bodycavity 51 while the opaque liquid 91 is removed from the area oftreatment. As illustrated in FIG. 22b , the handle 1012 may have anangle with respect to the frame 1014 to provide more room for aphysician's hand when the handheld device is held near an area oftreatment.

The transparent section can also be self-sealing such that the medicaltool 60 can be removed without opaque liquids 91 filling the puncturedsection of the transparent section 1018 previously occupied by the tool60. Additionally, the transparent section 1018 can be detachable fromthe handheld device 1010 such that after one use a new transparentsection 1018 can be installed after sanitizing the handheld device 1010.

The transparent section can comprise a material selected from the groupconsisting of silicone elastomers, silicone gels, albumin based gels,mineral oil based gels, poxies, polyurethanes, polyisoprene,polybutadiene, and mixtures thereof. The material can be a crosslinkedpolysiloxane. The material can be a hydrogel selected from the groupconsisting of polyvinyl alcohol, poly(hydroxyethyl methacrylate),polyethylene glycol, and poly(methacrylic acid).

Of course, the handheld device 1010 is not restricted to medicalapplications and may be used for other purposes, such as industrialapplications discussed above with respect to the optical couplers.

Thus, an optical coupler is provides for mounting on an endoscope,borescope, camera, or the like. The coupler provides improved opticalimaging of surfaces covered with opaque fluids, semisolid materials orparticulate matter.

Although the above devices have been described in considerable detailwith reference to certain embodiments, one skilled in the art willappreciate that the present description can be practiced by other thanthe described embodiments, which have been presented for purposes ofillustration and not of limitation. Therefore, the scope of the appendedclaims should not be limited to the description of the embodimentscontained herein.

What is claimed is:
 1. An optical coupler configured to cooperate withan endoscope, the optical coupler comprising; an attachment sectioncomprising one or more elastic material(s) and dimensioned to beremovably attached to a distal end of the endoscope; a visualizationsection in contact with the attachment section and at least partiallysurrounding a distal surface of the endoscope, the visualization sectionbeing configured to allow transmission of an optical image therethrough;and one or more supporting elements extending away from the attachmentsection or the visualization section.
 2. The optical coupler of claim 1,wherein the one or more supporting elements are elastic.
 3. The opticalcoupler of claim 1, wherein the one or more supporting elements extendlaterally away from the attachment section.
 4. The optical coupler ofclaim 1, wherein the optical coupler is configured for advancementthrough a lumen within a patient, the one or more supporting elementsbeing dimensioned to maintain the position of the optical couplerrelatively in the center of the lumen.
 5. The optical coupler of claim1, wherein the endoscope comprises a tube with a longitudinal axis, theone or more supporting elements extending at an angle transverse to thelongitudinal axis.
 6. The optical coupler of claim 1 wherein thevisualization section includes an outer surface extending distal to thedistal end of the endoscope.
 7. The optical coupler of claim 6, whereinthe outer surface is spaced apart from the proximal surface by a lengthequal to a reference distance selected from values in the depth of fielddistance range of the optical imaging system.
 8. The optical coupler ofclaim 7, wherein the reference distance is in the lower 10% of values inthe depth of field distance range of the optical imaging system
 9. Theoptical coupler of claim 6, wherein a portion of the outer surface iswithin a field of view of the optical imaging system when the attachmentsection is mounted at the distal end of the optical imaging system. 10.The optical coupler of claim 1, wherein the elastic material(s) have adurometer of from 40-95 on the Shore 00 scale.
 11. The optical couplerof claim 1, wherein the elastic material(s) are selected from the groupconsisting of silicone elastomers, silicone gels, albumin based gels,mineral oil based gels, epoxies, polyurethanes, polyisoprene,polybutadiene, crosslinked polysiloxane, polyvinyl alcohol,poly(hydroxyethyl methacrylate), polyethylene glycol, poly(methacrylicacid), and mixtures thereof.
 12. The optical coupler of claim 1, whereinthe attachment section is integral with the visualization section. 13.The optical coupler of claim 12, wherein the visualization section isdistal of the attachment section when the attachment section is coupledto the distal end of the endoscope.
 14. The optical coupler of claim 1,wherein the visualization section has a central opening overlying atleast a portion of the lens of the endoscope when the attachment sectionis coupled to the distal end of the endoscope.
 15. An optical imagingsystem for visualizing a surface area in a patient, the systemcomprising: an endoscope having an elongate flexible shaft with proximaland distal end and a lens at the distal end of the shaft; and an opticalcoupler comprising: an attachment section removably coupled to thedistal end of the endoscope and comprising one or more elasticmaterial(s); a visualization section in contact with the attachmentsection and at least partially surrounding a distal surface of theendoscope, the visualization section being configured to allowtransmission of an optical image from the lens therethrough; and one ormore supporting elements extending away from the attachment section orthe visualization section.
 16. The optical imaging system of claim 15,wherein the one or more supporting element are elastic.
 17. The opticalimaging system of claim 15, wherein the one or more supporting elementsextend laterally away from the attachment section.
 18. The opticalimaging system of claim 15, wherein the optical coupler is configuredfor advancement through a lumen within a patient, the one or moresupporting elements being dimensioned to maintain the position of theendoscope relatively in the center of the lumen.
 19. The optical imagingsystem of claim 15, wherein the one or more supporting elementsextending at an angle transverse to a longitudinal axis of the elongateflexible shaft.
 20. The optical imaging system of claim 15, wherein thevisualization section includes an outer surface extending distal to thedistal end of the endoscope.
 21. The optical imaging system of claim 15,wherein the outer surface is spaced apart from the lens of the endoscopeby a length equal to a reference distance selected from values in thedepth of field distance range of the optical imaging system.
 22. Theoptical imaging system of claim 21, wherein the reference distance is inthe lower 10% of values in the depth of field distance range of theoptical imaging system
 23. The optical imaging system of claim 21,wherein a portion of the outer surface is within a field of view of thelens when the attachment section is mounted at the distal end of theendoscope.
 24. The optical imaging system of claim 15, wherein theelastic material(s) have a durometer of from 40-95 on the Shore 00scale.
 25. The optical imaging system of claim 15, wherein the elasticmaterial(s) are selected from the group consisting of siliconeelastomers, silicone gels, albumin based gels, mineral oil based gels,epoxies, polyurethanes, polyisoprene, polybutadiene, crosslinkedpolysiloxane, polyvinyl alcohol, poly(hydroxyethyl methacrylate),polyethylene glycol, poly(methacrylic acid), and mixtures thereof. 26.The optical imaging system of claim 15, wherein the attachment sectionis integral with the visualization section.
 27. The optical imagingsystem of claim 26, wherein the visualization section is distal of theattachment section when the attachment section is coupled to the distalend of the endoscope.
 28. The optical imaging system of claim 15,wherein the visualization section has a central opening overlying atleast a portion of the lens of the endoscope when the attachment sectionis coupled to the distal end of the endoscope.